The present invention relates to a switching arrangement for an audio or magnetic tape recorder which is used to return the tape after a recording, unless it begins with the start of the tape, to its initial position at the beginning of the recording without having to remember the position of the counter where the recording was begun. A requirement is that the counter at the start of the recording be placed in its initial position which is achieved by striking a key. Such a disconnect arrangement which, in the initial position shuts off the counter, is not always in operation. Instead, it is operative only when the quick rewind of the tape is started.
Audio or magnetic tapes usually have a dead section, i.e. the beginning and end of the tape are formed by a section of tape which does not permit recording or playback. Therefore, at the start of a recording at the beginning of a tape, the tape must first be advanced by at least a portion of the dead section. This requires the following operations: First, the tape must be advanced, observing the counter or the tape itself, by a certain portion, and then the tape advance must be shut off. Thereafter the counter must be placed in the zero position.
In order to simplify this operation and to shorten the process, there is known a switching arrangement which shuts off the device automatically after running through the dead section, so that observation of the counter or of the tape and the manual shutoff can be dispensed with, but not the setting of the counter to zero. The time of shutoff is determined electronically. Such a device is relatively expensive and has the disadvantage that the time of shutoff with respect to tape length is subject to relatively large tolerances whose causes stem from the electrical time determining means, since the expense involved must not be too high, but also that the accelerations differ when the tape starts up. The result is that with this invention it is not possible to precisely relocate the start of an already recorded audio program automatically in the same manner. This is of importance when the playback or replay of a recording is to start at a fixed instant, i.e., that the pressing of the replay key coincides precisely with the start of replay, as is desired, for example, when fading in a recording.
It is, therefore, an object of the present invention to simplify the above switching arrangement and its handling, and to make it available for replay with precisely determinable starting times.
Another object of the present invention is to provide an arrangement of the foregoing character which may be economically fabricated and which has a substantially long operating life.
A further object of the present invention is to provide an arrangement, as described, which may be readily maintained in service.